Hi! Thanks Lila Pereszke! I've verified the tree is indeed Pink Cassia, also known as Cassia Nodosa with a common name "Pink Shower". The flowers are in full bloom these days (height of summer) in Islamabad but the tree is not common and considered to be still a rarity. I have located only a couple of them so far in this large city. Luckily I could find it in a nursery and happily paid for its somewhat high price for planting at my smamall farm near Islamabad. Thanks again for prompt reply and very correct identification. Iqbal